at idel my car reves up and down (ruhhhh uhhh ruhhhh uhhhhh)it just started doing it out of the blue. i thought it might have been a vacum leak or something like that but i cant find any leaks. could it be o2 sensors? if you can help i would apreciate it. oh yeah my car runs perfect oother than at idel. thanks

 

hehe oh yeah crx d15. peace

 

The guys above gave some good suggestions.
In order to know what is causing the problem though youre going to need to get a bit dirty and figure it out youself. Get some carb cleaner and with the engine running spray it around the intake manifold TB etc. If idle jumps youve found the problem.
If its a bad thermo valve when the engine is at op temp take off the FITV housing lid and stick your finger over the hole. If you feel suction then the wax pellet has become to old to expand and you will need to replace the FITV.
If none of that is the case it could be a sticking throttle plate (open a tad resulting in off-idle) leak in a vacuum line (use carb cleaner again) etc.

 

i had a bad PCV valve cause that in my old HF

 

it might be carborated then i guess that the idle air bypass isnt the problem

 

thanks for the help guys i will check it out today and if i figure it out ill let ya know. later

 

Did you do any fuel modifications?? When Cavy got some of her fuel mods done the idle got messed up. When I reved the motor the idle would fall and then fly back up. It would drop to like 200 rpms and then fly back up to around 1500rpms and then fall back down and stall sometimes. I got a FPR and it got alot better. I think I was running too much fuel.

 

I would have guessed either a PCV valve or a sticking throttle plate from past problems with my old civ.